SYS/BIOS: How to specify placement of shared variables?

David Aldrich

I am working on a C6670 project, using SYS/BIOS 6.32.4.49. I want to share variables between multiple cores using MSMCSRAM.

I understand how to specify a memory section within the MSMCSRAM segment and how to specify that variables should be placed in that section.

How do I guarantee that variables are placed in a section in the same order across multiple cores, so that they can be shared?

Best regards

David

over 13 years ago

0 judahvang over 13 years ago

TI__Mastermind 32475 points

David,

You should be able to place your section into a hard coded address instead of a "Memory Segment".
This would guarantee that the section is the same for all executables.

There might be other options too but a bit more complicated.

Judah

0 David Aldrich over 13 years ago in reply to judahvang

Expert 1345 points

Hi Judah,

Thanks. Please can you direct me to a document reference that explains how to do this?

However, even if we place the section at an explicit address, how do we guarantee that the linker orders variables in that section identically for multiple cores?

David

0 judahvang over 13 years ago in reply to David Aldrich

TI__Mastermind 32475 points

David,

I believe the compiler documentation describes how to place a variable in section and place the section in a memory segment/hard coded address.
See page 164 in http://www.ti.com/lit/ug/spru187t/spru187t.pdf

Do you have mulitple variables in the same section? If so then you are correct, I'm not sure if you are guaranteed to have same order for all programs.

Unless you have lots of variables, I would recommend you put each in its own section?

Judah

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SYS/BIOS: How to specify placement of shared variables?